title: Intrauterine growth restriction is associated with cardiac ultrastructural and gene expression changes related to the energetic metabolism in a rabbit model.
abstract: Intrauterine growth restriction (IUGR) affects 7-10% of pregnancies and is associated with cardiovascular remodeling and dysfunction, which persists into adulthood. The underlying subcellular remodeling and cardiovascular programming events are still poorly documented. Cardiac muscle is central in the fetal adaptive mechanism to IUGR given its high energetic demands. The energetic homeostasis depends on the correct interaction of several molecular pathways and the adequate arrangement of intracellular energetic units (ICEUs), where mitochondria interact with the contractile machinery and the main cardiac ATPases to enable a quick and efficient energy transfer. We studied subcellular cardiac adaptations to IUGR in an experimental rabbit model. We evaluated the ultrastructure of ICEUs with transmission electron microscopy and observed an altered spatial arrangement in IUGR, with significant increases in cytosolic space between mitochondria and myofilaments. A global decrease of mitochondrial density was also observed. In addition, we conducted a global gene expression profile by advanced bioinformatics tools to assess the expression of genes involved in the cardiomyocyte energetic metabolism and identified four gene modules with a coordinated over-representation in IUGR: oxygen homeostasis (GO: 0032364), mitochondrial respiratory chain complex I (GO:0005747), oxidative phosphorylation (GO: 0006119), and NADH dehydrogenase activity (GO:0003954). These findings might contribute to changes in energetic homeostasis in IUGR. The potential persistence and role of these changes in long-term cardiovascular programming deserves further investigation.
authors.affiliation: Fetal and Perinatal Medicine Research Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain;
authors.forename: Anna
authors.initials: A
authors.lastname: Gonzalez-Tendero
authors.forename: Iratxe
authors.initials: I
authors.lastname: Torre
authors.forename: Patricia
authors.initials: P
authors.lastname: Garcia-Canadilla
authors.forename: Fátima
authors.initials: F
authors.lastname: Crispi
authors.forename: Francisco
authors.initials: F
authors.lastname: García-García
authors.forename: Joaquin
authors.initials: J
authors.lastname: Dopazo
authors.forename: Bart
authors.initials: B
authors.lastname: Bijnens
authors.forename: Eduard
authors.initials: E
authors.lastname: Gratacós
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005317:Fetal Growth Retardation / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D015870:Gene Expression; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure; D010085:Oxidative Phosphorylation; D010920:Placenta / Q000378:metabolism* / Q000503:physiopathology; D011247:Pregnancy; D011817:Rabbits
keywords: cardiomyocyte intracellular organization; energetic metabolism; fetal cardiac programming; intracellular energetic units; intrauterine growth restriction